At the present, the pillow type automatic packing machines (vertical or horizontal) from all over the world are all using one roll of film to package one series of packing goods, so the working efficiency is quite low. In order to improve the packing speed largely and decrease the occupied space, a double track automatic packing machine is developed by combining a couple of pillow type automatic packing machines back-to-back and sharing a common frame in domestic manufacturer. It is a kind of block structure assembled by two automatic packing machines with one common frame. Except the common frame, all other assemblies, such as transmission system, electric system, electron optic tracking system, vertical proper sealing device and end sealing and cutting device are all two independent set of structures, moreover its adjusting, operating and control system are all independent respectively also. During the operation, a couple of rolls of film should be installed on the two machines separately, and the two machines work independently. Though the occupied space is decreased a little, the cost of manufacture and the number of operators is nearly the same as that of the two separate machines.